Pneumatic product-on-demand delivery systems have been used on agricultural seeding machines to automatically direct seed from a main seed hopper to a plurality of individual planting units. Each of the individual planting units has an auxiliary seed hopper for receiving the seed, a seed meter for metering the seed from the auxiliary seed hopper and a furrow opener for forming a planting furrow into which the metered seed is deposited. A fan is used to create pressurized air that forms an air stream on which the seed is taken to the planting units. These systems automatically replenish the auxiliary seed hoppers as needed.
One such system is described in U.S. Pat. No. 6,609,468, herein incorporated by reference. This product-on-demand delivery system comprises a frame having a main hopper and a plurality of application units. An air pump directs pressurized air to a manifold where the pressurized air is distributed to a plurality of air supply hoses. The air supply hoses are coupled to air inlets located on the bottom of the main hopper. Opposite the air inlets are corresponding product outlets for receiving the air streams and product entrained in the air streams. The product outlets are coupled to product supply hoses that are in turn coupled to auxiliary hoppers located on the application units. The bottom of the main hopper is concave and has outwardly diverging side walls. The air inlet is downwardly angled relative to the bottom and the product outlet is upwardly angled relative to the bottom.
Peaked baffles are located above corresponding air inlets and outlets so that product puddles form beneath the baffles. Gaps are formed between adjacent baffles so that product from the main hopper can flow into the product puddles.
The nozzle assembly is provided with an agitator assembly having a transverse rod that is provided with a plurality of radially extending fingers. The transverse rod is rotated back and forth by a gearbox/motor assembly. The radially extending fingers sweep the gaps between the individual baffles.
Planting systems have to handle many different types of seeds and many different treatments on the seed. Developing a single system that works well with all these different conditions without adjustment is difficult.
In the above-described seed-on-demand system, the agitator is configured to begin rotation when the planter is lowered to the ground and is unfolded. This is advantageous in order to ensure that seed is always delivered to the application units, even during the initial filling stage when the planter is not moving. However, the agitator, when used with easy flowing seed, will sometimes continue to push seed into the air stream which can eventually cause the system to plug the product hoses between the main hopper and the application units.
The present inventor has recognized that it would be desirable to provide a product-on-demand delivery system that has an increased reliability and a decreased requirement for operator control. The present inventor has recognized that it would be desirable to provide a product-on-demand delivery system that was effective to dispense a variety of seed types and conditions with a minimum of operator control and adjustment. The present inventor has recognized that it would be desirable to provide a product-on-demand delivery system that was effective to dispense a variety of seed types and seed conditions with a minimum of system plugging.